Weight and Height of 14 1/2 week old Boy

My son was born on the "small side" according to my doctor, he was 7 pounds 4 ounces and 18.5 inches. He is now 14 pounds 5 ounces and 24 inches which places him in the 53rd and like 21st percentile or something. I don't get the percentile thing, I just want to know if my baby is shorter than the average boy his age. My best friends son is 14 days younger exactly and he's like a pound bigger and an inch taller. I've looked it up and gotten so many mixed answers so I'm just curious where other baby's his age are at. Thanks :)